It's an alligator lizard. A little hard to tell from this picture but it lost its tail and regrew another one prior. The lizards chest was about handlebar size in diameter, really big!
Ha I was about to post my lizard knowledge...Some one gave me a alligator lizard years ago thinking it was an escaped pet. I ended up keeping it around in a cage (I had like ten snakes and lizards at the time) and it was pregnant so I raised about 10 little baby ones...they were so adorable...